1. School of Chemical and Biological Engineering, Seoul National University, Sillim‐9‐Dong, Gwanak‐Gu, Seoul 151‐744, Korea;2. Department of Electrical Engineering, Soongsil University, 511 Sangso‐Dong, Dongjak‐Gu, Seoul, 156‐743, Korea;3. School of Chemical and Biological Engineering, Seoul National University, Sillim‐9‐Dong, Gwanak‐Gu, Seoul 151‐744, KoreaSchool of Chemical and Biological Engineering, Seoul National University, Sillim‐9‐Dong, Gwanak‐Gu, Seoul 151‐744, Korea. Fax: +82 2 880 7070
Abstract:
We synthesized a series of polystyrene derivatives containing coumarin side groups using polymer analogous reactions. The liquid‐crystal (LC) alignment director for these polymer films was found to be perpendicular to the rubbing direction. The contrast ratio and anchoring‐energy values of these polystyrene derivatives were found to be much greater than those of polystyrene and poly(chloromethylstyrene), indicating that the coumarin side groups increase the aligning ability. For example, the anchoring energy of a polymer with 82 mol‐% of coumarin‐containing monomeric units, compared to polystyrene, is about 7 × 10?5 J · m?2 and 1 × 10?7 J · m?2, respectively.
